The recently approved nine-valent human papillomavirus (HPV) vaccine, Gardasil 9, potentially can prevent 80% of cervical cancers in the United States if given to all 11- or 12-year-old children before they are exposed to the virus, results of a new seven-center study suggest.
- The vaccine also has the potential to protect against approximately 19,000 other cancers diagnosed in the United States, including anal, oropharyngeal, and penile cancers, which is an 11.1% increase in protection against HPV-related cancers in comparison to the previously approved vaccines.
- The Vaccine Is Administered As Three Shots, With The Initial Dose Followed By Additional Shots Given Two And Six Months Later.
The recently approved nine-valent human papillomavirus (HPV) vaccine potentially can prevent 80% of cervical cancers in the United States if given to all 11- or 12-year-old children before they are exposed to the virus, results of a new seven-center study suggest.1 The vaccine also has the potential to protect against approximately 19,000 other cancers diagnosed in the United States, including anal, oropharyngeal, and penile cancers, which is an 11.1% increase in protection against HPV-related cancers in comparison to the previously approved vaccines.1
The Food and Drug Administration approved Gardasil 9 from Kenilworth, NJ-based Merck Sharp & Dohme Corp., a subsidiary of Merck & Co, in December 2014. The vaccine covers nine HPV types: HPV 6 and HPV 11, the two low-risk types that cause most cases of genital warts, as well as seven high-risk types: HPV 16, 18, 31, 33, 45, 52, and 58. The new vaccine is administered as three shots, with the initial dose followed by additional shots given two and six months later. (To read more about the vaccine, see the STI Quarterly supplement article, “New HPV vaccine covers 9 types of HPV,” inserted in the March 2015 issue of Contraceptive Technology Update.)
Details of study
The Centers for Disease Control and Prevention partnered with seven U.S. population-based cancer registries to obtain archival tissue for cancers diagnosed from 1993 to 2005. Scientists performed HPV testing on 2,670 case patients that were fairly representative of all participating cancer registry cases by age and sex. Researchers then evaluated demographic and clinical data by anatomic site and HPV status. Current U.S. cancer registry data and the detection of HPV types then were used to estimate the number of cancers potentially preventable through vaccination.
The research is the first comprehensive study of its kind and shows the potential not only to reduce the global cancer burden, but also to guide clinical decision-making with regard to childhood vaccinations, according to Marc Goodman, PhD, MPH, senior author of the study and director of cancer prevention and genetics at the Cedars-Sinai Samuel Oschin Comprehensive Cancer Institute in Los Angeles.
The study data suggest the nine-valent vaccine has the potential to protect against an additional 5.7% of oropharyngeal cancers, which include the base of the tongue and tonsils. This disease is the second most common HPV-associated cancer. “We found that 70% of patient DNA tissue samples with cancer of the oropharynx harbored HPV,” says Goodman. “This is a much higher percentage of HPV than observed in other studies, likely because of changes in sexual behaviors, such as increased oral-genital contact.”
The vaccine also was found to potentially increase protection from other HPV-related cancers including those of the vulva (48.6% to 62.8%), vagina (55.1% to 73.3%), penis (47.9% to 56.9%), and anus (79.4% to 87.6%).
What is the next step?
What does Goodman see as the next step in research in determining how well the current vaccines protect against HPV-associated cancers?
“The overarching goal is to monitor the impact of the HPV vaccine on the incidence of invasive cervical cancer and its precursors (defined as carcinoma in situ, cervical intraepithelial neoplasia 2-3, and adenocarcinoma in situ) in the United States as the cohort of the vaccinated population ages and vaccination coverage increases,” wrote Goodman in comments sent via email to Contraceptive Technology Update.
According to Goodman, recommendations for establishing an enhanced surveillance system include:
- systematically monitoring age-specific rates of invasive cervical cancer and other invasive HPV-associated carcinomas (which exists with the cancer registries). Other HPV-associated carcinomas include anal, penile, vulvar, vaginal, oropharyngeal, and oral cavity cancers.
- systematically monitoring age-specific rates of cervical cancer precursors and precursors for other HPV-associated cancers;
- identifying the distribution of HPV types, such as HPV-16 and HPV-18, associated with HPV-associated carcinoma precursors and invasive carcinoma;
- monitoring the incidence of invasive and preinvasive carcinomas along with the prevalence of vaccination. Linkages between cancer and immunization registries could provide data on the vaccine status of women with diagnoses of these cancers;
- explore and evaluate methods for linking cancer registry data with screening and risk factor data that already are being collected by other surveillance systems.
“Although some of the recommendations are existing activities, ultimately, the identified disparate resources need to be brought together under a single umbrella to maximize the utility of the aggregated information for public health surveillance,” says Goodman.
How to boost rates
A new study that compared the initiation and completion of the HPV vaccine among women in two Michigan community-based networks with electronic health records indicates that patients ages 9 to 18 were almost three times more likely to start the vaccine and 10 times more likely to complete the series if their health providers received automated prompts alerting them patients were due for a shot during any appointment. Patients ages 19-26 were six times more likely to start the vaccine and eight times more likely to complete the series, data indicate.2
“We found that simply alerting patients and providers during an office appointment increased uptake and completion of the HPV vaccine series,” said lead author Mack Ruffin IV, MD, MPH, professor of family medicine at the Ann Arbor-based University of Michigan Medical School, in a statement accompanying the study publication. “Our findings suggest that these prompts through the electronic health system may be a valuable tool in encouraging more people to protect themselves from cancer.”
- Saraiya M, Unger ER, Thompson TD, et al. US assessment of HPV types in cancers: Implications for current and 9-valent HPV vaccines. J Natl Cancer Inst 2015; doi: 10.1093/jnci/djv086.
- Ruffin MT 4th, Plegue MA, Rockwell PG, et al. Impact of an electronic health record (EHR) reminder on human papillomavirus (HPV) vaccine initiation and timely completion. J Am Board Fam Med 2015; 28(3):324-333.